In Vitro Antibacterial Activity of Green Synthesized Silver Nanoparticles Using Azadirachta indica Aqueous Leaf Extract against MDR Pathogens.

Rice is the most important staple food crop feeding more than 50% of the world's population. Rice blast is the most devastating fungal disease, caused by Magnaporthe oryzae (M. oryzae) which is widespread in rice growing fields causing a significant reduction in the yield. The present study was initiated to evaluate the effect of green synthesized silver nanoparticles (AgNPs) on the biochemical constituents of rice plants infected with blast. AgNPs were synthesized by using Azadirachta indica leaf extract and their characterization was performed using UV-visible spectroscopy, particle size analyser (PSA), scanning electron microscope (SEM), and X-ray diffraction (XRD) which confirmed the presence of crystalline, spherical shaped silver nanoparticles with an average size of 58.9 nm. After 45 days of sowing, artificial inoculation of rice blast disease was performed. After the onset of disease symptoms, the plants were treated with AgNPs with different concentrations. Application of nanoparticles elevated the activity of antioxidative enzymes such as superoxide dismutase, catalase, peroxidase, glutathione reductase, and phenylalanine ammonia-lyase compared to control plants, and total phenol and reducing sugars were also elevated. The outcome of this study showed that an increase in all biochemical constituents was recorded for A. indica silver nanoparticles-treated plants. The highest values were recorded in 30 ppm and 50 ppm AgNPs-treated plants, which showed the highest resistance towards the pathogen. Green synthesized AgNPs can be used in future for disease control in susceptible varieties of rice. The synthesized AgNPs using A. indica leaf extract have shown promising antibacterial activity when tested against 14 multidrug-resistant (MDR) bacteria comprising Gram-negative bacteria Escherichia coli (n = 6) and Klebsiella pneumoniae (n = 7) with a good zone of inhibition diameter, tested with the disc diffusion method. Based on these findings, it appears that A. indica AgNPs have promise as an antibacterial agent effective against MDR pathogens.

In vitro and in vivo inhibitory effects of Tabernaemontana alternifolia against Naja naja venom.

BACKGROUND: Tabernaemontana alternifolia root is traditionally used and practiced among few Indian tribes as an antidote for snakebites. OBJECTIVE: To combat and neutralize Naja naja venom using methanolic root extract of Tabernaemontana alternifolia and to explore its efficacy on venom biomarkers in search of newer herbal antidote or first-aid-point of care for therapeutics.Materialization.Pharmacological activities such as fibrinogenolytic, direct and indirect hemolytic activities for the neutralization of the venom were evaluated. Lethal toxicity annulation studies were performed using the murine model by pre-incubation and post-treatment protocols. Further, the neutralization of edema and myotoxicity were also evaluated. RESULTS: Electrophoretic analysis revealed that the complete neutralization of fibrinogen degradation was observed at 1:10 (w/w) (venom to extract). T. alternifolia exhibited an effective dose (ED50) value of 87.20 µg/mL for venom-induced hemolysis. Venom at 2 µg concentration produced 11 mm of hemolytic radiance and was neutralized at 1:20 (w/w) venom to extract concentration. The survival time and the neurotoxic symptoms in mice were concluded to be delayed by both the methods of lethal toxicity inhibition using methanol extract. The edema ratio reduced the venom to extract ratio of 1:20 (w/w) from 173 ± 45% to 133.61% when subjected to 5 µg of venom concentration. The plant extract significantly neutralized the myotoxic activity. CONCLUSION: T. alternifolia methanolic root extract could be a potent contributor in the effective treatment of N. naja venom-induced toxicity.

In Vitro Antibacterial Activity of Green Synthesized Silver Nanoparticles Using Mangifera indica Aqueous Leaf Extract against Multidrug-Resistant Pathogens.

An estimated 35% of the world's population depends on wheat as their primary crop. One fifth of the world's wheat is utilized as animal feed, while more than two thirds are used for human consumption. Each year, 17-18% of the world's wheat is consumed by China and India. In wheat, spot blotch caused by Bipolaris sorokiniana is one of the major diseases which affects the wheat crop growth and yield in warmer and humid regions of the world. The present work was conducted to evaluate the effect of green synthesized silver nanoparticles on the biochemical constituents of wheat crops infected with spot blotch disease. Silver nanoparticles (AgNPs) were synthesized using Mangifera indica leaf extract and their characterization was performed using UV-visible spectroscopy, SEM, XRD, and PSA. Characterization techniques confirm the presence of crystalline, spherical silver nanoparticles with an average size of 52 nm. The effect of green synthesized nanoparticles on antioxidative enzymes, e.g., Superoxide dismutase (SOD), Catalase (CAT), Glutathione Reductase (GR), Peroxidase (POX), and phytochemical precursor enzyme Phenylalanine Ammonia-Lyase (PAL), and on primary and secondary metabolites, e.g., reducing sugar and total phenol, in Bipolaris sorokiniana infected wheat crop were studied. Inoculation of fungal spores was conducted after 40 days of sowing. Subsequently, diseased plants were treated with silver nanoparticles at different concentrations. Elevation in all biochemical constituents was recorded under silver nanoparticle application. The treatment with a concentration of nanoparticles at 50 pp min diseased plants showed the highest resistance towards the pathogen. The efficacy of the green synthesized AgNPs as antibacterial agents was evaluated against multi drug resistant (MDR) bacteria comprising Gram-negative bacteria Escherichia coli (n = 6) and Klebsiella pneumoniae (n = 7) and Gram-positive bacteria Methicillin resistant Staphylococcus aureus (n = 2). The results show promising antibacterial activity with significant inhibition zones observed with the disc diffusion method, thus indicating green synthesized M. indica AgNPs as an active antibacterial agent against MDR pathogens.

Isolation and purification of a neurotoxin from Bungarus caeruleus (common Indian krait) venom: biochemical changes induced by the toxin in rats.

Bungarus caeruleus (Indian common krait) is a venomous snake that is responsible for most of the snakebites in India. In the present study, we report the isolation and purification of neurotoxin and the biochemical changes and pathological effects induced by injection of purified neurotoxin into rats. The purpose of this study was to compare the effects of crude krait venom and the purified toxin. Both the crude venom and a sublethal dose of 60 microg/kg B. caeruleus purified toxin significantly increased the serum levels of alkaline phosphatase, alanine aminotransferase, and urea (p < 0.05). The crude venom but not the purified toxin increased the levels of lactate dehydrogenase, aspartate aminotranseferase, creatine kinase, and glucose. The kidneys showed congestion of the vessels, hemorrhage, and necrosis in venom-injected but not in toxin treated animals. The results of this study indicate that although crude krait venom has severe lethal, hemorrhagic, nephrotoxic, and proteolytic activities, the purified neurotoxin shows only moderate toxic activity, manifested as prominent local and systemic effects.

In vitro screening and evaluation of antivenom phytochemicals from Azima tetracantha Lam. leaves against Bungarus caeruleus and Vipera russelli.

BACKGROUND: Snakebites are considered a neglected tropical disease that affects thousands of people worldwide. Although antivenom is the only treatment available, it is associated with several side effects. As an alternative, plants have been extensively studied in order to obtain an alternative treatment. In folk medicine, Azima tetracantha Lam. is usually used to treat snakebites. The present study aims to provide a scientific explanation for the use of this plant against snakebite. The extracts of shade dried leaves of A. tetracantha were tested for in vitro inhibitory activity on toxic venom enzymes like phosphomonoesterase, phosphodiesterase, acetylcholinesterase, hyaluronidase etc. from Bungarus caeruleus and Vipera russelli venoms. RESULTS: The ethylacetate extract rendered a significant inhibitory effect on the phosphomonoesterase, phosphodiesterase, phospholipase A2 and acetylcholinesterase enzymes. CONCLUSIONS: The present study suggests that ethylacetate extract of A. tetracantha leaves possesses compounds that inhibit the activity of toxic enzymes from Bungarus caeruleus and Vipera russelli venom. Further pharmacological and in vivo studies would provide evidence that this substance may lead to a potential treatment against these venoms.

In vitro screening and evaluation of antivenom phytochemicals from Azima tetracantha Lam. leaves against Bungarus caeruleus and Vipera russelli

Snakebites are considered a neglected tropical disease that affects thousands of people worldwide. Although antivenom is the only treatment available, it is associated with several side effects. As an alternative, plants have been extensively studied in order to obtain an alternative treatment. In folk medicine, Azima tetracantha Lam. is usually used to treat snakebites. The present study aims to provide a scientific explanation for the use of this plant against snakebite. The extracts of shade dried leaves of A. tetracantha were tested for in vitro inhibitory activity on toxic venom enzymes like phosphomonoesterase, phosphodiesterase, acetylcholinesterase, hyaluronidase etc. from Bungarus caeruleus and Vipera russelli venoms.

In vitro screening and evaluation of antivenom phytochemicals from Azima tetracantha Lam. leaves against Bungarus caeruleus and Vipera russelli

Snakebites are considered a neglected tropical disease that affects thousands of people worldwide. Although antivenom is the only treatment available, it is associated with several side effects. As an alternative, plants have been extensively studied in order to obtain an alternative treatment. In folk medicine, Azima tetracantha Lam. is usually used to treat snakebites. The present study aims to provide a scientific explanation for the use of this plant against snakebite. The extracts of shade dried leaves of A. tetracantha were tested for in vitro inhibitory activity on toxic venom enzymes like phosphomonoesterase, phosphodiesterase, acetylcholinesterase, hyaluronidase etc. from Bungarus caeruleus and Vipera russelli venoms.(AU)

In vitro screening and evaluation of antivenom phytochemicals from Azima tetracantha Lam. leaves against Bungarus caeruleus and Vipera russelli

Snakebites are considered a neglected tropical disease that affects thousands of people worldwide. Although antivenom is the only treatment available, it is associated with several side effects. As an alternative, plants have been extensively studied in order to obtain an alternative treatment. In folk medicine, Azima tetracantha Lam. is usually used to treat snakebites. The present study aims to provide a scientific explanation for the use of this plant against snakebite. The extracts of shade dried leaves of A. tetracantha were tested for in vitro inhibitory activity on toxic venom enzymes like phosphomonoesterase, phosphodiesterase, acetylcholinesterase, hyaluronidase etc. from Bungarus caeruleus and Vipera russelli venoms.